Means for operating the electric unloaders of air-compressors.



No. 815,025. I PA-TENTED MAR. 13, 1906. F. VAN D. LONGAORE.

MEANS FOR OPERATING THE ELECTRIC UNLOADERS OF AIR COMPRESSOR.

APPLICATION TILED NOV. 20, 1903.

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4, 4 CW Q No. 815,025. PATENTED MAR. 13, 1906. P. VAN D. LONGAGRE.

MEANS FOR OPERATING THE ELECTRIC UNLOADERS OF AIR GOMPRESSORS. APILIOATIOH FILED NOV. 20, 1903.

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No. 815,025. 'PATENTED MAR. 13, 1906. F. VAN n. LONGAGRE. MEANS FOR OPERATING THE ELECTRIC UNLOADERS OF AIR GOMPRESSORS.

APPLICATION FILED NOV. 20, 1903.

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m5 SEE 7 UNITED STATES PATENT OFFICE.

FREDERICK VAN DUZER LONGAORE, or NEW YORK, N. Y., ASSIGNOR TO THE INGERSOLL-SERGEANT DRILL COMPANY, or NEW YORK, N. YL, A

CORPORATION OF, WEST VIRGINIA.

MEANS FOR OPERATING THE ELECTRIC UNLOADERS O F AIR-COMPRESSORS.

Patented March 13, 1906.

Application filed November 20, 1903. Serial No. 181,985-

L aresident of the borough of Manhattan, in the city and State of New York, have invented a new and useful Means for Operating the Electric Unloaders of Air-Compressors, of which the following, is a specification.

My invention consists in means foroperating the electric unloader of an air-compressor.

My invention contemplates the provision of means for controlling the unloadlng of an alr-compressor beforestarting, so that the infor starting the compressor shall be re uced to as small an amount as possible for practical operation.

A further object is to provide means for operating the unloader so that the load is thrown .on when the motor and compressor reach a predetermined speed, the oint being determined by the connection of t e unloader with the rheostat resistance, forming part of my invention, so that the unloader will be output by the rheostat-arm at the point desire In the accompanying drawings, Figure 1 represents the electnc unloader in connection with which my means for operating it is used, the main valve and its ad acent parts'being shown in section.- Fi 2 is a transverse vertical sectionthrough t e unloader and valve,

r the parts being in the position which they assume when the current is off the unloader- Fig. 3 is a detail cross-section ing in the direction of the arrow. Fig. 3 is a similar view on the line B. Fig. 4 1s a diagrammatic view showin the automatic means which I have provided for operating the unloader. Fig. 5 1s a diagrammatic view showing the manually-operated means which I have shown for operatln the unloader, and Fi 6 is a detail sectionai View of one of the va ve-oaps.

The main valve of the air-compressor regu lator, which controls the opening and closing of the spaces back of the ischarge-valves to the atmosphere, is denoted by 1, its piston by 2, and its box by 3. The auxiliary slidevalve is denoted by4 and is located in a box 5 at one side of the valve-box 3. The supply ort to the auxiliary valve-box 5 is denoted y 5*. This auxiliary valve 4 controls the movement of the main valve 1 as followsz When the auxiliary slide-valve is at the limit of its downward movement, it will admit pressure to the proper side of the piston 20f the main valve 1 to cause it tomove the main valve into positionto open communication from the intercooler to the back of the lowpressure valve-ca of the compressor. When the auxiliary sli e-valve 4 is raised to the limit of its u ward movement, it will admit pressure to t e other side of the piston 2 of the main valve 1, thus sliding the main valve into position to open the backs of the highpressure valve-cap and low-pressure valve-cap to the exhaust or atmosphere.

The unloadin -casing 6 surmounts thecured upon the lower end of the bar 9 by nuts 12, between which collar and the bottom of the valve-box 5 a spring 13 is interposed, which serves to normally hold the bar 9, and thereby the auxiliary valve 4, at the limit of their downward movements.

The means which I have devised for automatically energizing and denergizing the electromagnet 7 for controlling the operation of the auxiliary valve 4, and thereby the movements of the main valve 1, is constructed, arranged, and operated as follows: I provide arr air-pressure-governed electric contactor 14, having the usual contacts 15 16 and oscillating finger 17. The motor is shown diagrammatically at 18. netlc clutch 19, which is positively driven from any suitable'source of power-as, for instance, the motorthrough connections not shown herein by a worm and gear con nection 21 22 and shaft 20. The coil of the magnetic clutch 19 is denoted conventionally by 26, which coil when ener ized serves to 0perate a link 27, connected arm 28 of a rheostat 29. A holding-ma net 30 is provided for the swinging arm 28 o the rheostat. I provide a magnetic-controlled contactor 31 with the usual coils 32 33, adapted to be short-circuited by the air-pressure- I provide a mag- IOC to the swinging governed electric contactor 14. I also provide a magnetic switch 34, its controllingcoil being denoted by 35. When both coils 32 33 are energized, the core 31 will not be moved, but will remain in either extreme position, depending upon which coil was energized last. The main-line switch is denoted by 36 and the line-wires leading therethrough by 37 38. The coil of an electric blow-out magnet for preventing sparkin in the magnetic switch 34 is herein denoted by 47.- Re

sistances 48 49 are located between the nega- 3 tive side of the main currentat the magnetic clutch 19 and the coils 32 and 33, respectively, of the magnetic-controlled contactor 31. A resistance 50 is also shown between the ma netic switch-controlling coil 35 and the hol ing-magnet 30.

The electric unloader is operated as follows: Let it be assumed that the airc0mpressor has stopped at a predetermined high pressure. As the air-pressure in the receiver alls the air-pressure-governed electric contactor 14 will cause the oscillating finger 17 to enga e the contact 15. This will shortcircuit t 1e coil 33 of the magnetic-controlled contactor 31 because oi' greater resistance in the coil 33 over a connection through point 15, thus allowing its core 39 to be drawn up by the coil 32 into engagement with the contact 40, thus completing the circuit through the controlling-coil 35, magnetic clutch-coil 26, and holding-magnet 30. Immediately upon contact being made in the magneticcontrolled contactor 31 the main circuit will be thrown in by the magnetic switch 34 at the point 41. As soon as this main contact is made at 41 the current is thrown onto the motor through the rheostat 29, and consequently throu h the electromagnet 7 of the unloader, whirfii electromagnet is part of the rheostat resistance. The energization of the electromagnet 7 raises the armature 8, and thereby the bar 9, thus moving the auxiliary valve4 into position to cause the main valve to be operated to open the spaces back of the high and low ressure valve-caps to the at mosphere, an thus unload the compressor. Sufficient current is provided through the first point of resistance in the rheostat 29 to allow the motor 18 to start. Upon the starting of the motor, and thereby the compressor,

the magnetic clutch 19 is operated", it being mechanically driven from the motor 18, as hereinbefore set forth. The operation of the ma netic clutch 19 serves to lift the link 27, an thereby swing the arm 28 of the rheostat, over the resistance-coils, thus cutting out the resistance in the rheostat and permitting the motor and compressor to gain speed. The arm 28 of the rheostat will finally be drawn into contact with the holding magnet 30, thereby cutting out all of the resistance of the rheostat. As soon as the rheostat-arm 28 comes in contact with the holding-magnet 5 30 the magnetic clutch-coil 26 is dee'nergized l because less resistance is presented through I the arm 28 to the opposite pole of the circuit 1 than through the magnetic clutch-coil. This i denergization of the clutch-coil 26 Will release the link 27 and permit the arm 28 of the i rheostat to drop as soon as the circuit is broken through the holding-magnet 30. The l electromagnet 7 of the unloader is connected in series with the rheostat resistance at some 1 pointas, for instance, at the last point of resistance'so that when the arm 28 of the rheostat reaches this point the electromagnet 7 of the unloader is cut out, and thereby i denergized. As soon as the electronia net 7 is denergized the auxiliary valve 4 will be moved back to its normal position at the limit of its downward movement, thus moving the main valve into position to throw the load onto the compressor. In the accompanying drawings the relation of the parts is such that the motor and compressor are per mitted to reach practically full speed before the loadis thrown ontothe compressor. After the'load has been thrown onto the cornpressor and the air-pressure in the receiver has risen to a predetermined. high-pressure point the oscillating finger 17 of theair-pressuregoverned electric contact will engage the contact 16, and thereby short-circuit the coil 32 in the magnetic-controlled contactor 31, thus breaking the circuit through the core 39 and contact 40. This will immediately release the magnetic switch 34 and break the main circuit through the motor at the point 41, thereby releasing the entire apparatus. The current throu h the holding-magnet 30 is also broken by t e breaking of the circuit between the core 39 and contact 40, thus ermitting the arm 28 of the rheostat to fa l to its normal position. The compressor will thereby remain loaded until the means for operatin the electric unloader is again brought into use.

In Fig. 5 I have shown a diagrammatic view illustrating a hand starting device for operating the electric unloader. In this instance when the main switch 36 is closed a circuit will be established through the rheostat 29, and thereby throu h the electromagnet 7 of the unloader. T e arm 28 of the rheostat may then be moved by hand to successively cut out the resistance-coils of the rheostat. ing m'agnet 30 the motor, and thereby the compressor, will-have attained full speed and the electromagnet 7 of the unloader is cut out, thus throwing the load onto the compressor.

What I claim is- 1. An air-compressor, a discharge-valve therefor, a main regulator-valve for controlling the pressure behind the discharge-valve, an auxiliary valve for controlling the movements of the main regulator-valve, an electromagnet for operating the auxiliary valve As the arm 28 reaches the hold- 1 and means for energizing and denergizing the electromagnet.

2. A main re ulator-valve for an air-compressor, an auxi 'ary valve for controlling the movements of the same, an electromagnet for operating the auxiliary valve and airpressure-controlled means for permitting the energization and denergization of the electromagnet.

3. An unloader for an air-compressor and electrically-controlled means for operating the unloader comprising a rheostat, an elec-' tromagnet connected in series therewith and arranged to be deenergized when the rheostat-arm reaches a predetermined point.

4. An unloader for an air-compressor and electrically-controlled means for operating the unloader comprising a rheostat, an e1ec tromagnet connected in series therewith and a holding-magnet for the rheostat-arm 5. An unloader for an air-compressor and electrically-controlled means for operating the unloader comprising a rheostat, an electromagnet connected in series therewith, a magnetic clutch for controlling the. movement of the rheostat-arm, a motor for operating the magnetic clutch when the circuit is completed therethrough and air-pressurecontrolled means formaking and breaking the circuit.

6. An unloader for an air-compressor and electrically-controlled means for operating jtromagnet connected in series therewith, a

magnetic clutch, a motor for driving the same, a magnetic-controlled contactor, a

magnetic switch and an air-pressure-governed electric contactor formaking and breaking the circuit through the several parts.

8. An unloader for an air-compressor and electrically-controlled means for operating it comprising a rheostat, .a holdingmagnet for the rheostat-arm, a magnetic clutch for moving the arm, a motor connected to the magnetic clutch, a magnetic controlled contactor, a magnetic switch and an air-pressuregoverned electric contactor for controlling the operation of the several parts.

In testimony that I claim the foregoing as my invention I have signed my name, in presence of two witnesses, this 21st day of October, 1903. p

FREDERICK "AN DUZER LONGAORE.

Witnesses:

FREDK. HAYNEs, 'HENRY THIEME. 

